1. Field of the Invention
This invention relates to a recording method for recording the locus of a light spot on a heat-mode recording medium.
2. Description of the Prior Art
This type of recording method is used, for instance, in recording the locus of a flying object. To cite a specific example, a laser light spot or the like used to represent a flying object is made to move over a heat-mode recording medium in a path corresponding to the course of the flying object, thereby to record the locus of the flying object on the recording medium.
By a heat-mode recording medium is meant a recording medium whereon information is recorded as a change in the optical characteristics of the medium within the regions of the recording layer thereof thermally modified such as by fusion, evaporation or condensation when a beam of light with high energy density such as a laser beam is directed thereon, the thermal modification of the recording layer being caused primarily by the heat of the beam with high energy density. The heat-mode recording medium used in this invention may be one of those disclosed in Japanese Unexamined Patent Publication Nos. 78236/1976, 20821/1977 or 83617/1978 but is not limited to these and may be of any type whatever.
Heat-mode recording mediums are advantageous in that they do not have to be developed and that the recording operation can be carried out in a light room or under a bright safety light. As a result, they are being used more and more widely in place of photosensitive materials employing silver salts. However, when a heat-mode recording medium is used to record the locus of a flying object which moves at varying speeds, there arises the drawback that the line image recorded on the medium to represent the locus of the flying object will not be of uniform thickness. For example, assume that the recording operation is carried out using a laser beam directed onto the recording layer of the medium so as to cause certain regions of the layer to fuse and, through this fusion, become transparent to light. Now, if the speed of the flying object varies, this will cause a corresponding variation in the exposure time of the recording layer along the path of the laser beam thereon. Therefore, since the laser beam is of constant intensity, the thickness of the line image representing the locus of the flying object will vary in accordance with the variation in the speed of the flying object.